<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        .list-wrap {
            width: 300px;
            height: 500px;
            background: #ccc;
        }

        .list li {
            width: 100px;
            height: 30px;
            background: red;
            color: #fff;
            text-align: center;
            line-height: 30px;
            list-style: none;
            float: left;
            margin: 10px;
        }

        .list-wrap2 .list li {
            background: green;
            width: 100%;
        }
    </style>
</head>

<body>
    <div class="list-wrap">
        <ul class="list">
            <li>列表</li>
            <li>列表</li>
            <li>列表</li>
            <li>列表</li>
            <li>列表</li>
        </ul>
    </div>
</body>

</html>